In 3D-coordinate measurement technology, points are measured not only directly, but also indirectly. This is normally done with adapters which can be purchased from various manufacturers as accessories. The technology is established on the market and is mainly employed for measurements with 3D coordinate measuring machines. In the process, a drilling is, for example, adapted such that the intersecting point of the cylinder axis with a plane extending at right angles with respect to it corresponds to the point to be determined at a defined distance along the cylinder axis.
As for measurements for example with a laser tracker, a spherical retroreflector is used, such an adapter must possess a housing which is e.g. a section of a ball or a cone to fix the probe element at a defined distance. In measurements with a laser tracker, retroreflectors with varying diameters are used, so that for the adaptation of a drilling, several adapters (drilling adapters) for different retroreflector diameters are required. Basically, retroreflector diameters of 0.5″ and 1.5″, less common also 0.875″, are here usual. There are several different standard values for the bore diameters, for example 6, 8, 10, 12, 14, 16, 18 mm.
Up to now, one adapter each was required for each bore diameter for the two or three retroreflector diameters. To be able to use two different retroreflectors e.g. for seven different bore diameters, a set of 14 adapters is required. This is disadvantageous as in particular the adapters for the large retroreflector diameter of 1.5″ are expensive and heavy.